Edison in 1902 started to Gold Mould cylinders, this process uses a oversized groove and a large wax master. The master is placed in a vacuum with 2 pieces of gold leaf. High voltage is introduced to the gold leaf in the bell jar, and vaporizes...

Edison in 1902 started to Gold Mould cylinders, this process uses a oversized groove and a large wax master. The master is placed in a vacuum with 2 pieces of gold leaf. High voltage is introduced to the gold leaf in the bell jar, and vaporizes...